Ideally it would be a drop in replacement type, with 5V supply and supporting TTL logic.

Can anyone help?

The place to ask this question is on a HAM radio forum. Lots of people with good experience in designing these. No, none of the cans are any good. You will need some discrete parts.

They can be quire complex with temperature controlled housings. So before you ask the question think hard about the specs you really need. What kind of over all stability, what about phase noise? What accuracy is required?

Have a look at the Driscoll oscillator, particularly Chris Bartram GW4DGUs paper discussing a third overtone version, obviously component values will change, and you will probably be working fundamental mode, but the basic idea is there.

Layout will (as ever with RF) be critical, as will choice of components, dielectrics and such.